This Small Business Innovation Research Phase I project proposal addresses the development of a digital holographic microscope, for the non-invasive inspection of micro-mechanical structures. Micro-mechanical systems are being employed in various commercial devices such as, pressure sensors, accelerometers, flow valves, switches, relays, micro-motors and micro-manipulators. Traditional methods used to evaluate the structural integrity of macro-mechanical structures can not be implemented with micro-mechanical structures. This problem calls for new non-destructive, non-invasive techniques for the inspection and quality control of micro-mechanical structures. We propose to develop a digital holographic system, which can evaluate the structural integrity of micro-mechanical structures with minimum operator interaction and training. Structural integrity will be evaluated by studying the deformation of micro-structures under operating stresses. The instrument will employ the principle of holographic interferomery to measure deformation fields. lnterferograms will be recorded using a video camera and the deformation fields will be extracted from the interferograms using digital image processing techniques. Digital holography, when combined with digital image processing will yield full-field deformation/strain field information in quasi-real time. A digital holographic microscope will be highly beneficial tool for the design and inspection of micro-mechanical structures. We expect to have a high demand for this instrument in computer hardware, instrumentation and materials industries and also in academic and industrial research community. Specific areas of application include : (1) design and inspection of microelectro-mechanical systems (NIEMS), (2) deformation analysis of electronic substrates, and (3) micro-mechanics study of composite materials.
